c) Two departments of size ten ({a1,..., a10} and {b1, .., b10}) choose two members to participate in a committee a;, a;, b; and b;. The committee has a chair, but no other members are ranked. How...

Discrete math probability answer C please

Extracted text: c) Two departments of size ten ({a1,..., a10} and {b1, .., b10}) choose two members to participate in a committee a;, a;, b; and b;. The committee has a chair, but no other members are ranked. How many unique committees exist? (e.g. Chair: a2, Members: a3, b2, bg is an example)